The Danish study, on more than 21,000 couples seeking In vitro fertilisation (IVF) treatment, found women who were unsuccessful in having a child were four times more likely to die prematurely than those who had been mothers.

However, critics have stressed that the risk of early death was low - with just 316 people in total dying over the 11 year study, the 'BBC News' reported.

Researchers also point out that the study suggests a link between childlessness and premature death and not a cause.

"Mindful that association is not the same thing as causation, our results suggest that the mortality rates are higher in the childless," they said.

The study findings are based on data obtained from various population registers in Denmark on births, deaths and IVF procedures from 1994 to 2005.

As many as 21,276 childless couples registered for IVF treatment, 15,149 children were born and a total of 96 women and 220 men died.

The results suggested having a child cut the risk of early death, particularly among women.

Researchers found that childless women were four times more likely to die early from circulatory disease, cancers, and accidents than those with children- and men were about twice as likely.

"This is a very specific situation of people who are trying to have children - the study's findings cannot be used to generalise across the whole general population," Ingrid Collins, a consultant psychologist, said.

"People having IVF tend to be desperate for a child, if they are unsuccessful they may be depressed- it may even be this rather than childlessness that is playing a part. One can only guess.

Others have also pointed out that a family can psychologically help and support those that are dying.